# USB Standard-B receptacle

> a class of legacy USB receptacles that preceded USB-C (“B” indicating the peripheral device end)

**Wikidata**: [Q133871409](https://www.wikidata.org/wiki/Q133871409)  
**Source**: https://4ort.xyz/entity/usb-standard-b-receptacle

## Summary
The USB Standard-B receptacle is a class of legacy USB ports located on the peripheral device end of a connection, designed to accept a Standard-B plug. It preceded the modern USB-C standard and is technically distinct from other form factors like Standard-A, Micro-B, and Mini-B receptacles. This receptacle type serves as the chassis-side component of the USB Standard-B connector family.

## Key Facts
*   **Definition:** A class of legacy USB receptacles designed for the peripheral device end of a connection ("B" designation).
*   **Historical Context:** Preceded the USB-C standard.
*   **Classification:** It is a subclass of the "USB Standard-B connector," "USB Standard receptacle," and "USB Type-B receptacle" classes.
*   **Variations:** Specific related instances include the USB 2 Standard-B receptacle and the USB 3 Standard-B receptacle.
*   **Differentiation:** It is distinct from the USB Standard-B plug (the cable connector), as well as USB Standard-A, USB Micro-B, and USB Mini-B receptacles.
*   **Visual Resource:** An official illustration exists depicting the USB 3 and USB 2 Standard-B receptacles to scale.

## FAQs
### Q: What is the primary function of a USB Standard-B receptacle?
A: It serves as the port on a peripheral device (such as a printer or hard drive) that accepts the "B" end of a USB cable, connecting the peripheral to a host.

### Q: How does the USB Standard-B receptacle differ from the USB Standard-B plug?
A: The receptacle is the chassis-mounted port located on the device, whereas the plug is the cable-mounted connector that inserts into it.

### Q: Is the USB Standard-B receptacle still current technology?
A: No, it is classified as a legacy component that preceded the development of the modern USB-C standard.

## Why It Matters
The USB Standard-B receptacle represents a critical phase in the evolution of connectivity standards, specifically defining the "peripheral" side of the Universal Serial Bus architecture before the unification brought by USB-C. Its existence allowed for the distinct separation of host devices (which typically used Standard-A) from peripheral devices, enforcing a specific directionality in data and power flow. While now considered legacy technology, the Standard-B receptacle was foundational in establishing reliable hardware connections for a wide range of electronics for decades. It bridges the gap between the original USB implementations and modern reversible connectors, serving as the physical interface for billions of devices manufactured prior to the USB-C transition.

## Notable For
*   **Classifying the Peripheral End:** Specifically indicating the "B" or device-side connection point in USB architecture.
*   **Legacy Status:** Being the direct predecessor to USB-C in the Standard-B form factor lineage.
*   **Form Factor Variations:** Encompassing distinct physical iterations for USB 2.0 and USB 3.0 standards.
*   **Distinct Hierarchy:** Existing as a specific subclass within the broader USB Type-B and USB Standard connector families.

## Body
### Classification and Hierarchy
The USB Standard-B receptacle is a specific class of interface classified as a "USB Standard-B connector" and a "USB Type-B receptacle." It belongs to the broader category of "USB Standard receptacles." In the context of hardware evolution, it is designated as a legacy component that functionally preceded the USB-C standard. The "B" designation specifically indicates its role at the peripheral device end of a connection, distinct from the "A" end found on hosts.

### Technical Variations
This receptacle class includes specific hardware iterations, most notably the **USB 2 Standard-B receptacle** and the **USB 3 Standard-B receptacle**. While both fall under the "Standard-B" class, they represent different generations of the technology. The official nomenclature recognizes the entity simply as "USB Standard-B receptacle."

### Comparison with Related Connectors
The USB Standard-B receptacle is technically defined by what it is not. Structured data explicitly differentiates it from:
*   **USB Standard-B plug:** The cable connector counterpart.
*   **USB Standard-A receptacle:** The host-side port.
*   **USB Micro-B receptacle:** A smaller, mobile-oriented variant.
*   **USB Mini-B receptacle:** An earlier miniaturized variant.

Visual documentation of these legacy receptacles is standardized in technical illustrations that group USB 2 and USB 3 Standard-B receptacles to scale.

## References

1. [Source](https://www.usb.org/document-library/usb-31-legacy-cable-and-connector-revision-10)
2. [Source](https://www.usb.org/document-library/usb-type-cr-cable-and-connector-specification-release-24)
3. [Source](https://www.usb.org/document-library/usb-32-revision-11-june-2022)
4. [Source](https://www.usb.org/document-library/usb-type-cr-connectors-and-cable-assemblies-compliance-document-rev-21b)
5. [Source](https://www.usb.org/document-library/universal-serial-bus-31-legacy-connectors-and-cable-assemblies-compliance-document)